fix: cose-bilkent as the default layout for mindmaps

on-behalf-of: @Mermaid-Chart <hello@mermaidchart.com>

cypress/integration/rendering/mindmap-tidy-tree.spec.js

@@ -3,7 +3,10 @@ import { imgSnapshotTest } from '../../helpers/util.ts';
 describe('Mindmap Tidy Tree', () => {
   it('1-tidy-tree: should render a simple mindmap without children', () => {
     imgSnapshotTest(
-      `
+      ` ---
+      config:
+        layout: tidy-tree
+      ---
       mindmap
       root((mindmap))
         A
@@ -13,7 +16,10 @@ describe('Mindmap Tidy Tree', () => {
   });
   it('2-tidy-tree: should render a simple mindmap', () => {
     imgSnapshotTest(
-      `
+      ` ---
+      config:
+        layout: tidy-tree
+      ---
       mindmap
       root((mindmap is a long thing))
         A
@@ -25,7 +31,10 @@ describe('Mindmap Tidy Tree', () => {
   });
   it('3-tidy-tree: should render a  mindmap with different shapes', () => {
     imgSnapshotTest(
-      `
+      ` ---
+      config:
+        layout: tidy-tree
+      ---
       mindmap
       root((mindmap))
         Origins
@@ -49,7 +58,10 @@ describe('Mindmap Tidy Tree', () => {
   });
   it('4-tidy-tree: should render a mindmap with children', () => {
     imgSnapshotTest(
-      `
+      ` ---
+      config:
+        layout: tidy-tree
+      ---
        mindmap
       ((This is a mindmap))
         child1

cypress/platform/mindmap-layouts.html

@@ -362,6 +362,10 @@
     <hr />
     <script type="module">
       import mermaid from '/mermaid.esm.mjs';
+      import tidytree from '/mermaid-layout-tidy-tree.esm.mjs';
+      import layouts from './mermaid-layout-elk.esm.mjs';
+      mermaid.registerLayoutLoaders(layouts);
+      mermaid.registerLayoutLoaders(tidytree);
       mermaid.initialize({
         theme: 'default',
         logLevel: 3,

packages/mermaid/src/preprocess.ts

@@ -29,7 +29,7 @@ const processFrontmatter = (code: string) => {
     config.gantt.displayMode = displayMode;
   }
   if (diagramType === 'mindmap' && !config.layout) {
-    config.layout = 'tidy-tree';
+    config.layout = 'cose-bilkent'; // Default layout for mindmap
   }
   return { title, config, text };
 };